MONTPELIER — The Vermont Senate unanimously approved a bill this week that would require police to release investigation records that are currently not available to the public, cheering open-government advocates who have long criticized law enforcement with ducking public scrutiny by operating behind closed doors.

The bill, which was crafted by the Senate Judiciary Committee, passed 29-0 in a roll call vote, after State Sen. Dick Sears, chairman of the committee, told lawmakers that the bill was a “big deal,” according to Allen Gilbert, executive director for the Vermont chapter of the American Civil Liberties Union. It now heads to the State House of Representatives, where lawmakers are expected to take it up before the session expires.

“People have to realize, the position we’re all in now is that nobody has access to any criminal investigation records, even if the case is closed, or the suspect is dead,” Gilbert said in an interview this week. “We’re currently in a total shroud of secrecy situation, and the bill would move away from that.”

The bill was initially proposed by Gov. Peter Shumlin and has been touted by open-government advocates as a needed dose of accountability for law enforcement. Under current law, police typically assert a blanket right to keep the records of all investigations sealed. Under the bill, records would generally be made public absent a specific finding of “harm” that their release would cause. That would bring Vermont law in line with federal laws.

But supporters did not get everything they wanted.

At the urging of the Vermont League of Cities and Towns and other groups, the bill included stipulations that allow the names of witnesses and victims of crimes to be withheld.

The Shumlin administration and the ACLU opposed the exemptions, deeming them unnecessary. The proposed law included protections for “unwarranted invasion of personal privacy.” Moreover, it could potentially allow authorities to withhold names of people targeted by police use of force that is later deemed illegal.

“There’s always a danger when you create a categorical exemption,” Gilbert said. “There might be times when who a witness is can be important to how you understand a case. We’d rather have a court determine whether or not to release a witness or victim’s name rather than say ‘You can’t do it,’ categorically.”

Additionally, the Shumlin administration voiced concern that the new protections could allow not only people, but companies and agencies to have their identities redacted from police records.

Vermont’s public records law, which generally allows citizens to access all manner of government records, contains an exemption for records of “detection and investigation of crime.”

That exemption has routinely been invoked by police when refusing to release files from cases that have been closed, or never resulted in criminal charges. For example, Hartford police, backed by Sorrell’s office, declined to release files from two incidents in which officers were alleged to have used excessive force against citizens who were later found not to have committed any crimes.

Critics argue the current law allows the police to operate with little oversight, and leads to the Vermont attorney general’s office clearing officers of criminal wrongdoing without showing the public how they reached those conclusions.

Several legal experts who, at the request of the Valley News last year, reviewed a file of a Vermont State Police investigation into Hartford police officers accused of assaulting a naked and unconscious Wilder man said that state police appeared to soft-pedal the inquiry and only spotlight facts that reflected favorably upon the actions of police officers. (The Valley News obtained the file from confidential sources — police declined to release the file, citing the legal exemption.)

Under the bill, those files would now likely be released, advocates say.

The bill will likely be reviewed by the House Judiciary Committee and the House Government Operations Committee before it moves to the full House for a vote.

State Rep. Donna Sweaney, D-Windsor, the chairwoman of the government operations committee, said she is in favor of making police records more transparent.

“If you’re speaking about individual police records or investigative records ... we need to have a standard procedure to say yes, they are open records,” Sweaney said in an interview.